Oakland and Boston, the two highest-scoring teams in baseball, square off today for what shapes up as a most exciting American League Championship Series. With major league power-hitting leader Jos'e Canseco (42 homers, 124 RBIs) heading a lineup that includes fellow long-ball threats Mark McGwire (32 homers), Dave Henderson (24), Dave Parker, and Don Baylor, the A's can outslug just about anyone.

The Red Sox can't match those power statistics, but actually have a more productive offense overall. Wade Boggs, baseball's best hitter at .366, leads off a batting order that has basically no weak spots. Mike Greenwell (.325, 22 home runs, 119 RBIs), Dwight Evans (.294, 21, 111), and Ellis Burks (.295, 18, 92) are the biggest guns - but far from the only ones. Second baseman Marty Barrett (.283) and shortstop Jody Reed (.293) are both excellent on-base men, while Todd Benzinger, Rich Gedman, Jim Rice, and Larry Parrish assure manager Joe Morgan of enough strong hitters to keep the pressure on all the way through the lineup.

Oakland doesn't send up an array like that all the way down the line, but with catalysts Luis Polonia and Carney Lansford setting things up for Canseco &amp; Co., it comes pretty close. The A's scored 800 runs this year for an average of nearly five per game - a figure bettered only by Boston, which scored 813 times and also led the majors in team batting at .283.

Anyway you look at it, that's a lot of offense to jam into one ballpark - especially a hitter's paradise like Fenway Park, where the best-of-seven series opens today. But before assuming that this means a lot of 14-12 or 10-9 slugfests, one should note that both teams also have the kind of pitching that can shut down even the most formidable batting order. Consider, for example, that two-time Cy Young Award winner Roger Clemens isn't even No. 1 on the current Boston staff - and that two of the top candidates for this year's Cy Young honors - Dave Stewart and Dennis Eckersley - pitch for Oakland.

Stewart (21-12) will open the series for the A's against left-hander Bruce Hurst (18-6), who has emerged as Boston's top hurler this season. Storm Davis (16-7) goes against Clemens (18-12) in Game 2 Thursday night, with Bob Welch (17-9) facing Mike Boddicker (7-3 since joining Boston in a July 29 trade) when the series shifts to Oakland Saturday.

Both teams also have outstanding bullpens led, respectively, by Eckersley, who topped the majors with 45 saves, and Lee Smith, who had 29.

With all that talent on both sides, the series looks very much up for grabs. The Red Sox have more postseason experience, with 11 holdovers from the 1986 American League champions, but they also have a few sobering statistics staring them in the face.

The big one is that over the last few years this team has found it just about impossible to win in Oakland, with only one victory in its last 15 games there, including an 0-6 record this season. Fortunately for the Red Sox, they have the home advantage in the playoffs, and thus could conceivably win the series even if they lose all three road games. But still those numbers are not exactly comforting.

The A's are much more at home in Fenway Park, which isn't surprising since (a)the short left field wall is made to order for their array of right-handed power hitters and (b)four of their key performers - Lansford, Eckersley, Henderson, and Baylor - formerly played for Boston, with the latter two having been key members of the 1986 World Series team. (Baylor, incidentally, could wind up in the Series for a third year in a row, having played last year for Minnesota).

Anyway, Oakland was 3-3 in Boston this year for a 9-3 overall regular-season margin. The A's also outscored the Sox head to head, 58-43, outhit them .285-.251, and outhomered them by an overpowering 13-1 tally.

In other words, it was no contest. It's a long-established fact in baseball, however, that regular-season comparisons frequently turn out to be meaningless once the playoffs begin.

For whatever it may be worth, though, Oakland also had a much better overall record this year. The A's rolled to the West Division championship with a best-in-baseball 104 victories, Boston struggled to the East title with one of the lowest win totals (89) ever recorded by a division champion. Manager Tony La Russa's charges showed impressive consistency, too, while the Red Sox were so streaky and erratic that they seemed like several different teams. For half the campaign they were basically a .500 club; for several weeks right after Morgan took over the reins from John McNamara in midseason they were a virtually unbeatable juggernaut; then in the latter portion they cooled off again, although they managed to hang on for the title.

On balance, Oakland seems to have the more solid, consistent, dependable team - one that can beat you almost any way (with power, speed, pitching, or defense), and that will almost certainly come out and play a good, strong series. Boston's hot-and-cold team is a lot harder to figure - but if the Red Sox hit one of their ``up'' cycles at the right time, it will be quite a battle.